Valve with unobstructed flow path having increased flow coefficient

ABSTRACT

A valve comprising a valve body including a first end and a second end spaced apart along a longitudinal axis, a central portion disposed between the first end and the second end, wherein the first end and the second end define a first flow passageway and a second flow passageway, respectively, and wherein the central portion defines an interior chamber, wherein the first end of the valve body includes a bore, a valve seat disposed in the bore including a concave seating surface, and a disc rotatable within the interior chamber between an open position and a closed position, wherein the disc includes a seal having a shape corresponding to the concave seating surface and wherein the shape of the seal and the concave seating surface define an elliptical offset from a centerline of the valve.

TECHNICAL FIELD

The present disclosure relates generally to a valve, and in particularto a triple-offset valve with an unobstructed flow path and having anincreased flow coefficient (Cv).

BACKGROUND

Valves typically include a disc that sits in the center of the valve inthe flow path and rotates to regulate the rate of flow media. Suchvalves often are configured with a shaft or stem that passes through thecenter of the valve and is used to rotate the disc. The shaft/discassembly may be rotated by an operator/actuator (e.g., quarter turnrotation) between open and closed valve positions. Typically, the discis positioned in the flow path, with the disc oriented either parallelwith the valve flow centerline (open position) or perpendicular to thevalve flow centerline (closed position). The obstruction to the flowcaused by the presence of the disc and shaft along the valve flowcenterline may induce a pressure drop even when the valve is full openin the parallel orientation, thus reducing the maximum achievable flowcoefficient (Cv) of the valve. Valves may be configured in a zerooffset, double offset or triple offset configuration, with the latterconfiguration best suited for high-pressure systems requiring lowtorque, frictionless metal to metal sealing.

SUMMARY

This disclosure relates to a valve with an unobstructed flow path andhaving an increased flow coefficient.

In one aspect, one embodiment of a valve includes a valve body havingfirst and second ends spaced apart along a longitudinal axis and acentral portion disposed between the first and second ends. The firstand second ends define first and second flow passageways respectively,and the central portion defines an interior chamber. A stem is rotatablysupported by the valve body about a rotation axis. A disc is coupled tothe stem. The disc is rotatable within the interior chamber between aclosed position, wherein the disc closes one of the first or second flowpassageways, and an open position, wherein at least one of the first andsecond flow passageways is completely unobstructed between the first andsecond ends of the valve body when projected along the longitudinalaxis.

In another aspect, in one embodiment of a valve, the stem includes afirst stem portion supported by a top of the valve body and a secondstem portion supported by a bottom of the valve body, wherein the firstand second stem portions are spaced apart on opposite sides of, and donot project into the first and second flow passageways when projectedalong the longitudinal axis. The first and second stem portions areco-axial and define a rotation axis.

In another aspect, one embodiment of a method of operating a valveincludes rotating a disc in a valve body about a rotation axis betweenan open position and a closed position, wherein the valve body includesfirst and second ends spaced apart along a longitudinal axis and acentral portion disposed between the first and second ends, wherein thefirst and second ends define first and second flow passagewaysrespectively, and wherein the central portion defines an interiorchamber. The disc closes one of the first or second flow passageways inthe closed position, and at least one of the first and second flowpassageways is completely unobstructed between the first and second endsof the valve body when projected along the longitudinal axis when thevalve is in the open position.

In another aspect, one embodiment of a valve includes a valve bodyhaving first and second ends spaced apart along a longitudinal axis anda central portion disposed between the first and second ends, whereinthe first end comprises a bore. A valve is moveably disposed in thecentral portion, wherein the valve is moveable between open and closedpositions. A seat ring is disposed in the bore and defines at least inpart a flow passageway. A locator interfaces between the seat ring andthe body to positionally locate the seat ring relative to the body.

In another aspect, a unibody valve includes a valve body including afirst end and a second end spaced apart along a longitudinal axis and acentral portion disposed between the first end and the second end,wherein the first end and the second end define a first flow passagewayand a second flow passageway, respectively, and wherein the centralportion defines an interior chamber. The unibody valve further includesa disc disposed within the interior chamber, wherein the interiorchamber includes an enlarged side portion positioned outside of the atleast one of the first flow passageway and the second flow passagewayprojected along the longitudinal axis, wherein the disc is disposed inthe enlarged side portion when in an open position.

In another aspect, a valve includes a valve body including a first endand a second end spaced apart along a longitudinal axis and a centralportion disposed between the first end and the second end, wherein thefirst end and the second end define a first flow passageway and a secondflow passageway, respectively, and wherein the central portion definesan interior chamber. The valve further includes a stem rotatablysupported by the valve body about a rotation axis, wherein the stemincludes a polygonal end. The valve further includes a disc disposedwithin the interior chamber and including a polygonal aperture toreceive the polygonal end of the stem.

In another aspect, a valve includes a valve body including a first endand a second end spaced apart along a longitudinal axis and a centralportion disposed between the first end and the second end, wherein thefirst end and the second end define a first flow passageway and a secondflow passageway, respectively, and wherein the central portion definesan interior chamber, wherein the first end of the valve body includes abore. The valve further includes a removable seat disposed in the boreand defining at least in part the first flow passageway.

The various embodiments of the valve, and the methods for the usethereof, provide significant advantages over other valves and methods ofmanufacture and use. For example and without limitation, the disclosedvalve leaves the flow passageway unobstructed and thereby achieves ahigher flow coefficient. In addition, the seat ring may be easilyreplaced, for example if worn or damaged, or if the valve is beingreconfigured. The locator ensures that the seat ring is properly locatedrelative to the valve body, such that it is positionally located tointerface with the disc in the closed position.

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document. The term “couple” and its derivativesrefer to any direct or indirect communication or interaction between twoor more elements, whether or not those elements are in physical contactwith one another. The terms “include” and “comprise,” as well asderivatives thereof, mean inclusion without limitation. The term “or” isinclusive, meaning and/or. The phrase “associated with,” as well asderivatives thereof, means to include, be included within, interconnectwith, contain, be contained within, connect to or with, couple to orwith, be communicable with, cooperate with, interleave, juxtapose, beproximate to, be bound to or with, have, have a property of, have arelationship to or with, or the like. The phrase “at least one of,” whenused with a list of items, means that different combinations of one ormore of the listed items may be used, and only one item in the list maybe needed. For example, “at least one of: A, B, and C” includes any ofthe following combinations: A, B, C, A and B, A and C, B and C, and Aand B and C.

Definitions for other certain words and phrases are provided throughoutthis patent document. Those of ordinary skill in the art shouldunderstand that in many if not most instances, such definitions apply toprior as well as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of this disclosure and its advantages,reference is now made to the following description, taken in conjunctionwith the accompanying drawings, in which:

FIG. 1A illustrates a side perspective view of a triple valve assemblyin accordance with various embodiments of this disclosure;

FIG. 1B illustrates a downstream end view of a triple valve assembly inaccordance with various embodiments of this disclosure;

FIG. 1C illustrates an upstream end view of a triple valve assembly inaccordance with various embodiments of this disclosure;

FIG. 2A illustrates a side perspective view of a triple valve assemblyincluding a seat ring in accordance with various embodiments of thisdisclosure;

FIG. 2B illustrates a downstream end view of a triple valve assemblyincluding a seat ring in accordance with various embodiments of thisdisclosure;

FIG. 2C illustrates a side view of a triple valve assembly including aseat ring in accordance with various embodiments of this disclosure;

FIG. 3A illustrates an exploded top perspective view of a triple valveassembly in accordance with various embodiments of this disclosure;

FIG. 3B illustrates an exploded side view of a triple valve assembly inaccordance with various embodiments of this disclosure;

FIG. 3C illustrates an exploded bottom perspective view of a triplevalve assembly in accordance with various embodiments of thisdisclosure;

FIG. 4A illustrates a cross-sectional perspective view of a triple valveassembly in a closed position in accordance with various embodiments ofthis disclosure;

FIG. 4B illustrates a cross-sectional side view of a triple valveassembly in a closed position in accordance with various embodiments ofthis disclosure;

FIG. 4C illustrates a cross-sectional side view of a triple valveassembly in an open position in accordance with various embodiments ofthis disclosure;

FIG. 4D illustrates a cross-sectional top view of a triple valveassembly in a closed position in accordance with various embodiments ofthis disclosure;

FIG. 4E illustrates a cross-sectional top view of a triple valveassembly in an open position in accordance with various embodiments ofthis disclosure;

FIG. 5A illustrates a cross-sectional side view of a triple valveassembly showing an internal profile of a valve body in accordance withvarious embodiments of this disclosure;

FIG. 5B illustrates another cross-sectional side view of a triple valveassembly showing an internal profile of a valve body and with a seatring installed in accordance with various embodiments of thisdisclosure;

FIG. 5C illustrates a cross-sectional top view of a triple valveassembly showing an internal profile of a valve body in accordance withvarious embodiments of this disclosure;

FIG. 5D illustrates another cross-sectional top view of a triple valveassembly showing an internal profile of a valve body and with a seatring installed in accordance with various embodiments of thisdisclosure;

FIG. 6 illustrates a retainer ring in accordance with variousembodiments of this disclosure;

FIG. 7 illustrates a perspective view of a seat ring in accordance withvarious embodiments of this disclosure;

FIG. 8A illustrates a side view of an elliptical seal ring in accordancewith various embodiments of this disclosure;

FIG. 8B illustrates a perspective view of an elliptical seal ring inaccordance with various embodiments of this disclosure;

FIG. 9A illustrates a cross-sectional view of a triple valve assemblyshowing one example of a triple offset in accordance with variousembodiments of this disclosure;

FIG. 9B illustrates an example elliptical third offset from theperspective of seat ring in accordance with various embodiments of thisdisclosure;

FIG. 9C illustrates an example elliptical third offset from theperspective of a seal ring in accordance with various embodiments ofthis disclosure;

FIG. 9D illustrates an enlarged view of a first portion of a seal ringin accordance with various embodiments of this disclosure;

FIG. 10A illustrates an end view of a valve disc in accordance withvarious embodiments of this disclosure;

FIG. 10B illustrates a side view of a valve disc in accordance withvarious embodiments of this disclosure;

FIG. 10C illustrates a perspective view of a shaft in accordance withvarious embodiments of this disclosure;

FIG. 10D illustrates a perspective view of a valve disc in accordancewith various embodiments of this disclosure; and

FIG. 10E illustrates a perspective view of a valve disc installed on ashaft in accordance with various embodiments of this disclosure.

DETAILED DESCRIPTION

FIGS. 1A through 10E, discussed below, and the various embodiments usedto describe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artwill understand that the principles of this disclosure may beimplemented in any suitably arranged device or system.

It should be understood that the term “plurality,” as used herein, meanstwo or more. The terms “outboard” and “inboard” refer to the relativeposition of different features relative to a common axis or plane. Theterm “coupled” means connected to or engaged with, whether directly orindirectly, for example with an intervening member, and does not requirethe engagement to be fixed or permanent, although it may be fixed orpermanent (or integral). The terms “first,” “second,” and so on, as usedherein are not meant to be assigned to a particular component sodesignated, but rather are simply referring to such components in thenumerical order as addressed, meaning that a component designated as“first” may later be a “second” such component, depending on the orderin which it is referred. For example, a “first” diameter may be laterreferred to as a “second” diameter depending on the order in which theyare referred. It should also be understood that designation of “first”and “second” does not necessarily mean that the two components or valuesso designated are different, meaning for example a first diameter may bethe same as a second diameter, with each simply being applicable toseparate components. The terms “vertical” and “horizontal” refer to theorientation of various components as shown in the drawings, but with theunderstanding that those components may be rotated and used in otherorientations.

FIGS. 1A-1C illustrate an example triple offset valve assembly 2 inaccordance with various embodiments of this disclosure. FIG. 1Aillustrates a side perspective view of the triple valve assembly 2 inaccordance with various embodiments of this disclosure. FIG. 1Billustrates a downstream end view of the triple valve assembly 2 inaccordance with various embodiments of this disclosure. FIG. 1Cillustrates an upstream end view of the triple valve assembly 2 inaccordance with various embodiments of this disclosure.

The triple offset valve assembly 2 includes a one-piece valve body 4having a central portion 6 and a pair of end portions 8, 10 spaced apartalong a longitudinal axis 12 on opposite sides of the central portion.It should be understood that the body may include a plurality of piecescoupled together, including for example and without limitation, atwo-piece body, including a lower portion and an upper portion coupledthereto with fasteners. In general, the body and other components of thevalve described herein may be made of steel, such as an alloy/carbonsteel.

The end portions 8, 10 may have the same, or different lengths. Each endportion includes a tubular portion 16, 18 and an annular flange 20, 22,with the tubular portions defining an interior flow passageway 24extending along a longitudinal axis 12 between opposite ends of thebody. The flow passageway 24 is defined in part by an interior flowpassageway 26, 28 formed in each of the end portions. The flowpassageways 26, 28 may be cylindrical, defined by the interior surfaceof the end portions. The first and second flow passageways 26, 28 arecoaxial along the longitudinal axis 12 in one embodiment, and haverespective first and second cross-sectional areas defined orthogonal tothe longitudinal axis 12, with the first cross-sectional area being thesame as the second cross-sectional area in one embodiment.

A neck portion 34, which may be cylindrical, extends upwardly from thecentral portion. The neck portion includes an upper flange 36, shown asa rectangular plate, defining a top surface defining a top of the body.As shown in FIG. 1C, a disc 54 within the interior of the valve body 4is coupled to a first shaft 66 and a second shaft 64 (not shown), whichare coaxially aligned and rotatably mounted to the valve body 4 at upperand lower locations about a rotation axis 68. The stem 66 extendsupwardly through a passageway of the neck portion 34, with an upper endthereof positioned to be coupled to an operator/actuator.

The stem 64 (not shown) is rotatably supported by a bottom hub 70 of thebody, with a cover 72 (and bearing/bushing) secured thereto withfasteners 76 to support the stem 64. One or more bearings, seals,packing and/or bushings, collectively mounting members, may support thestems 64, 66 in the valve body 4, with the upper stem 66 extendingupwardly through the neck portion 34. In this way, the disc shaftincludes the first stem portion 66 supported by the valve body 4 andcoupled to a top of the disc 54, and the second stem portion 64supported by the valve body 4 and coupled to a bottom of the disc 54.The first and second stem portions 66, 64 are spaced apart on oppositesides of, and do not project into, the first and second flow passageways26, 28 projected along the longitudinal axis 12.

FIGS. 2A-2C illustrate an example triple valve assembly 2 including aremovable seat ring 30 in accordance with various embodiments of thisdisclosure. FIG. 2A illustrates a side perspective view of the triplevalve assembly 2 including the seat ring 30 in accordance with variousembodiments of this disclosure, FIG. 2B illustrates a downstream endview of the triple valve assembly 2 including the seat ring 30 inaccordance with various embodiments of this disclosure, and FIG. 2Cillustrates a side view of the triple valve assembly 2 including theseat ring 30 in accordance with various embodiments of this disclosure.

In some embodiments, the seat ring 30 is installed in the downstream endportion 10, with the seat ring 30 defining the flow passageway 28 havinga cross-sectional area the same as, and coaxial with, thecross-sectional area of the flow passageway 26 defined by the oppositeupstream end portion 8 configured without a seat ring. In someembodiments, the seat ring 30 may be omitted, with the flow passagewaysboth defined by the valve body 4. A retainer ring 110 and sealingcomponent 112 (not shown) are coupled to the valve body 4 to secure theseat ring 30 after it is positionally located. The retainer ring 110secures the seat ring 30 in place, with the sealing component 112clamped between the retainer ring 110 and an end of the seat ring 30. Insome embodiments, the shape of the seat ring 30 with respect to theshape of the flow passageway 28 allows for self-centering of the seat.In some embodiments, the retainer ring 110 is threaded to an interiorportion of the flange 22 to tighten and secure the retainer ring 110 andthe seat ring 30 to the valve body 4. Since the seat ring 30 is aseparate installable component from the valve assembly 2, and can beremoved by first loosening and removing the retainer ring 110, easiermaintenance and/or replacement of the seat ring 30 or the retainer ring110 is provided.

As shown in FIG. 2B, at the end 10 near the installation of the seatring 30 and retainer ring 110, the passageway 28 is sealed by the disc54 when the valve assembly 2 is in the closed position. In someembodiments, the disc 54 includes a seal retainer disc 60 and aplurality of fasteners 62, e.g., bolts and washers, that secure theretainer disc 60 to the disc 54.

As shown in FIG. 2C, the flow passageways 26, 28 may be cylindrical,defined by the interior surface of the end portions 8, 10, for exampledefined by a diameter (D) of the passageway 26, 28. A flow media, e.g.,fluids, flow through the valve from the upstream end portion 8 to thedownstream end portion 10, with the upstream end portion 8 having agreater length (L1) than the length (L2) of the downstream end portion10. It should be understood, however, that the valve may bebi-directional, and/or that the flow may proceed in the oppositedirection, with the end portion 8 being the downstream end portion andthe end portion 10 being the upstream end portion. The first and secondflow passageways 26, 28 are coaxial along the longitudinal axis 12 inone embodiment, and have respective first and second cross-sectionalareas defined orthogonal to the longitudinal axis 12, with the firstcross-sectional area being the same as the second cross-sectional areain one embodiment.

FIGS. 3A-3C illustrate example exploded views of the triple valveassembly 2 in accordance with various embodiments of this disclosure.FIG. 3A illustrates an exploded top perspective view of the triple valveassembly 2 in accordance with various embodiments of this disclosure.FIG. 3B illustrates an exploded side view of the triple valve assembly 2in accordance with various embodiments of this disclosure. FIG. 3Cillustrates an exploded bottom perspective view of the triple valveassembly 2 in accordance with various embodiments of this disclosure.

The triple valve assembly 2 includes a disc assembly 50. The discassembly 50 is configured as a laminate structure that includes anelliptical seal ring 52, the seal carrier or disc 54 with two disc arms56, 58 that conform to the outboard diameter of the valve, a sealretainer disc 60 and a plurality of fasteners 62 (bolts and washers)that secure the retainer disc 60 to the disc 54, with the ellipticalseal ring 52 clamped therebetween. In this way, the seal ring 52 isremovably coupled to the disc 54, such that it may be replaced if wornor damaged. For example, an operator may remove the fasteners 62 and theseal ring 52 and install a new seal ring, securing the seal ring withthe seal retainer disc 60 and fasteners 62. The seal ring 52 engages avalve seat created by the seat ring 30 when the valve and disc 54 are inthe closed position. It should be understood that, in some embodiments,the disc assembly 50, including the disc 54, arms 56, 58, stems 64, 66,and sealing element 52, may be made as a single piece, or the disc 54,arms 56, 58, and sealing element 52 may be made as a single piece, whichis connected to the stems 64, 66. The gaskets and sealing elements maybe made of graphite and/or commercial grade stainless steel.

The disc assembly 50 is coupled to the pair of stems/shafts 64, 66,which are coaxially aligned and rotatably mounted to the valve body atupper and lower locations about the rotation axis 68. The stem 66extends upwardly through the neck portion 34, with an upper end thereofpositioned to be coupled to an operator/actuator. The stem 64 isrotatably supported by a bottom hub 70 of the body, with a cover 72 (andbearing/bushing) secured thereto with fasteners 76 to support the stem64. One or more bearings, seals, packing and/or bushings, collectivelystem seal members 120, may support the stems in the valve body, with theupper stem extending upwardly through the neck portion. In this way, theassembly 2 includes a first stem or shaft 66 supported by the valve bodyand coupled to a top of the disc 54, and includes a second stem or shaft64 supported by the valve body and coupled to a bottom of the disc 54.The first and second stem portions 66, 64 are spaced apart on oppositesides of, and do not project into, the first and second flow passageways26, 28 projected along the longitudinal axis 12. In some embodiments,the connections of the stems 66, 64 to the disc are polygonal, such thatthe openings or apertures in the disc 54 at the disc arms 56, 58 are ina polygonal shape that matches the shapes of the corresponding shafts64, 66. The polygonal connections between the shafts 64, 66 and disc 54provide 100% torque transmission, and provides during installationverification that the shafts 64, 66 are correctly installed into theopenings of the disc 54, since the matching polygonal shapes of theshafts 64, 66 and the openings of the disc 54 ensure that the shafts 64,66 are installed in a proper orientation.

The laminate disc assembly 50, having a covered dome shape, and the sealring 52 in particular, or elliptical profile, mating with the concavelyshaped valve seat, having a corresponding elliptical profile, defined bythe seat ring 30. The configuration of the disc assembly 50 is designedto allow frictionless opening and closing of the disc assembly to reducethe required torque needed to move or stroke the valve between open andclosed positions. The seal ring 52 is installed onto the disc andsecured in place by a series of bolts/fasteners 62, as disclosed above.The disc 54 includes the first and second arms 56, 58, which aresituated tangentially to the disc, thereby ensuring that the position ofthe arms 56, 58 is outside the flow path of the media, or flowpassageways 26, 28 projected along the longitudinal axis 12. The discarms 56, 58 are mounted on the stems/shafts 66, 64, with the stem/shafts66, 64 being rotated by an operator or actuator, which rotates the discassembly 50 between the closed position and the open position.

The valve may be operated by any combination of a hand wheel, gearoperator or actuator. The actuator may be powered either electrically orpneumatically and may include a gearbox for applications where hightorque is required to operate the valve.

After the disc assembly 50 is installed, the seat ring 30 may beinserted into a bore defined by the valve body 4 and positionallylocated (e.g., non-rotatably) relative to the valve body 4 and bore witha locator 102. The seat ring 30 thereafter defines at least in part theflow passageway 28. The locator 102 interfaces between the seat ring 30and the body 4. After the locator pin 102 is installed, the seat ring 30is non-rotatably located or positioned relative to the valve body 4. Thelocator pin 102 ensures that the seat ring is installed into the body 4so that the valve seat offsets are oriented in the same direction as theseal ring 52 of the disc 54. Without the locator pin 102, the seat ringmay inadvertently be installed improperly, which would preclude sealingagainst the disc 54 and seal ring 52. By making the seat ring 30non-integral with the valve body 4, the seat ring may be formed, forexample by machining, separately from the valve body, and the seat ringmay be easily replaced if damaged. It should be understood that thevalve body 4, seat ring 30, and locator 102 may be used in differenttypes of valves other than a valve, including for example and withoutlimitation, gate valves, ball valves, etc.

A retainer ring 110 and sealing component 112 are coupled to the valvebody 4 to secure the seat ring 30 after it is positionally located. Theretainer ring 110 secures the seat ring 30 in place, with the sealingcomponent 112 clamped between the retainer ring and the end of the seatring 30. An outboard end of the locator pin 102 is covered by thesealing component and retainer ring, such that it may not be removed.The retainer ring 110 and seat ring 30 have inner surface diameters onthe downstream end that match the inner diameter of the valve on theupstream end, with the flow passageways defined thereby being alignedand co-axial, in order to reduce pressure drop across the valve, therebymaximizing the flow coefficient (Cv). The sealing component 112eliminates the potential for a leak path between the body 4, seat ring30, and retainer ring 110 when the valve is pressurized by the flowmedia, including for example a fluid.

FIGS. 4A-4E illustrate cross-sectional views of the triple valveassembly 2 in accordance with various embodiments of this disclosure.FIG. 4A illustrates a cross-sectional perspective view of the triplevalve assembly 2 in a closed position in accordance with variousembodiments of this disclosure. FIG. 4B illustrates a cross-sectionalside view of the triple valve assembly 2 in a closed position inaccordance with various embodiments of this disclosure. FIG. 4Cillustrates a cross-sectional side view of the triple valve assembly 2in an open position in accordance with various embodiments of thisdisclosure. FIG. 4D illustrates a cross-sectional top view of the triplevalve assembly 2 in a closed position in accordance with variousembodiments of this disclosure. FIG. 4E illustrates a cross-sectionaltop view of the triple valve assembly 2 in an open position inaccordance with various embodiments of this disclosure.

Various embodiments of the triple valve assembly 2 include a centralportion 6 defining an interior chamber 32 or cavity. The flowpassageways 26, 28 may be cylindrical, defined by the interior surfaceof the end portions 8, 10, for example defined by a diameter (D) of thepassageway 26, 28. A flow media, e.g., fluids, flow through the valvefrom the upstream end portion 8 to the downstream end portion 10. Itshould be understood, however, that the valve may be bi-directional,and/or that the flow may proceed in the opposite direction, with the endportion 8 being the downstream end portion and the end portion 10 beingthe upstream end portion. The first and second flow passageways 26, 28are coaxial along the longitudinal axis 12 in one embodiment, and haverespective first and second cross-sectional areas defined orthogonal tothe longitudinal axis 12, with the first cross-sectional area being thesame as the second cross-sectional area in one embodiment.

In some embodiments, a seat ring 30 is installed in the downstream endportion 10, with the seat ring defining the flow passageway 28 having across-sectional area the same as, and coaxial with, the cross-sectionalarea of the flow passageway 26 defined by the opposite upstream endportion 8 configured without a seat ring. In other embodiments, the seatring 30 may be omitted, with the flow passageways both defined by thevalve body. The interior chamber 32 includes a belly pocket or anenlarged side portion 14 positioned outside of at least one of the firstand second flow passageways 26, 28, and preferably both when configuredwith the same diameter, projected along the longitudinal axis 12. Theneck portion 34 defines an interior passageway 38 extending between thecavity and the top surface.

In some embodiments, the seat ring 30 is disposed in one of the endportions, e.g., the downstream end portion 10. The seat ring has atubular or cylindrical shape, with an outboard end 40 and an inboard end42. The inner circumferential surface 44 of the seat ring defines inpart the flow passageway 28, and is aligned with and has the samediameter as the inner circumferential surface of the other end portion,which defines the flow passageway 26, such that the flow passageways 26,28 define the same cross-section when projected along the longitudinalaxis. The inboard end 42 of the seat ring defines an elliptical seatingsurface, or valve seat 46, which is non-integral with the valve body anddoes not obstruct the flow path. Before the seat ring 30 is installed,the interior passageway of the outboard end portion 10 of the valve bodyis configured with an oversized diameter to accommodate the seat ring 30(e.g., the outer diameter thereof), which also provides additional spaceand allows for easier assembly of the valve internal components prior tothe seat ring 30 being installed in the end portion 10. It should beunderstood in other embodiments, the seat ring 30 may be omitted, withthe flow passageway 26 and valve seat 46 being formed integrally in thevalve body.

The disc assembly includes the elliptical seal ring 52, the disc 54 withtwo disc arms 56, 58 that conform to the outboard diameter of the valve,and the seal retainer disc 60. The disc 54 is coupled to the pair ofstems/shafts 64, 66, which are coaxially aligned and rotatably mountedto the valve body at upper and lower locations about the rotation axis68. The stem 66 extends upwardly through the passageway 38 of the neckportion, with an upper end thereof positioned to be coupled to anoperator/actuator. The stem 64 is rotatably supported by the bottom hub70 of the body, with the cover 72. The first and second stem portions66, 64 are spaced apart on opposite sides of, and do not project into,the first and second flow passageways 26, 28 projected along thelongitudinal axis 12.

The seat ring 30 defines at least in part the flow passageway 28. Invarious embodiments, the seat ring 30 is self-centering due to the shapeof the seat ring 30 and the internal profile of the valve. Additionally,as shown in FIG. 4E, the locator 102 interfaces between the seat ring 30and the body 4 to facilitate placement of the seat ring 30. In oneembodiment, the locator 102 is configured as a locator pin, which isdisposed in a first opening 106 of the valve body 4 and a second opening108 disposed in an outer surface of the seat ring 30. In other words,the seat ring 30 is non-rotatably/positionally located such that thepartial openings 106, 108 formed in each of the valve body 4 and seatring 30 are aligned to form an opening sized and shaped to receive thelocator pin 102. After the pin 102 is installed, the seat ring 30 isnon-rotatably located or positioned relative to the valve body 4. Thelocator pin 102 ensures that the seat ring is installed into the body sothat the valve seat offsets are oriented in the same direction as theseal ring 52 of the disc 54. As described herein, by making the seatring 30 non-integral with the valve body, the seat ring may be formed,for example by machining, separately from the valve body, and the seatring may be easily replaced if damaged.

The retainer ring 110 and sealing component 112 are coupled to the valvebody 4 to secure the seat ring 30 after it is positionally located. Invarious embodiments, the retainer ring 110 is threaded into an interiorcircumferential surface of the flange 22 of the end portion 10 of thevalve body 4 to secure the seat ring 30 in place, with the sealingcomponent 112 clamped between the retainer ring 110 and the end of theseat ring 30. An outboard end of the locator pin 102 is covered by thesealing component 112 and retainer ring 110, such that it may not beremoved unless intended to be removed by a replacement operation.

In operation, a method of operating the valve includes rotating the disc54 in the valve body 4 about the rotation axis 68 between the openposition and the closed position, and vice versa. As shown in FIGS. 4A,4B, and 4D, the disc 54 closes the flow passageways 28, 24 in the closedposition, with the seal ring 52 engaging the valve seat 46 when thevalve and disc are in the closed position. As shown in FIGS. 4C and 4E,when the disc 54 rotates about the rotation axis 68 to the openposition, at least one of the first and second flow passageways 26, 28are completely unobstructed between the first and second ends of thevalve body when projected along the longitudinal axis 12 when the valveis in the open position. In various embodiments, the disc 54 is rotatedwithin the interior chamber 32, wherein during rotation the first andsecond stem portions 66, 64 are spaced apart on opposite sides of, anddo not project into, the first and second flow passageways 26, 28projected along the longitudinal axis 12. In the open position, the flowmedium, for example a fluid such as a liquid, may flow through the flowpassageway 24. Because the flow passageway 24 is unobstructed by thedisc 54 and stems 64, 66, the flow coefficient (Cv) is maximized, andcan be up to 5 times greater than conventional valves. When in the openposition, the disc 54 moves into a belly pocket of the valve body 4defined by the unibody internal profile of the triple valve assembly 2,such that the flow path is unobstructed, allowing for the increased flowcoefficient and piggability of the triple valve assembly 2.Additionally, since the shafts 64, 66 are separate shafts that do notrun across the interior of the valve body 4, the shafts 64, 66 also donot obstruct the flow paths.

FIGS. 5A-5D illustrate various views of the triple valve assembly 2showing the internal profile of the valve body 4 in accordance withvarious embodiments of this disclosure. FIG. 5A illustrates across-sectional side view of the triple valve assembly 2 showing theinternal profile of the valve body 4 in accordance with variousembodiments of this disclosure. FIG. 5B illustrates anothercross-sectional side view of the triple valve assembly 2 showing theinternal profile of the valve body 4 and with the seat ring 30 installedin accordance with various embodiments of this disclosure. FIG. 5Cillustrates a cross-sectional top view of the triple valve assembly 2showing the internal profile of the valve body 4 in accordance withvarious embodiments of this disclosure. FIG. 5D illustrates anothercross-sectional top view of the triple valve assembly 2 showing theinternal profile of the valve body 4 and with the seat ring 30 installedin accordance with various embodiments of this disclosure.

In various embodiments of this disclosure, the triple valve assembly 2is cast as a unibody structure. The unibody structure of the triplevalve assembly 2 provides an internal profile providing variousbenefits. For example, the valve body 4 includes the belly pocket orside portion 14 disposed in a portion of the interior chamber 32 of thevalve body 4 outside of the flow paths 24, 26, 28, creating astreamlined flow path in which, when the disc 54 is in the openposition, the disc 54 resides within the cavity 14 and is thus movedentirely out of the flow paths 24, 26, 28. In this way, the disc 54 doesnot obstruct the flow path 24, 26, 28 in the open position.

In particular, the disc 54 is rotatable within the interior chamber 32between a closed position, wherein the disc 54 closes the second flowpassageway 28, and an open position, wherein the flow passageways arecompletely unobstructed between the first and second ends 8, 10 of thevalve body 4. The disc 54 and arms 56, 58 are disposed in the sideportion 14 of the cavity when the valve is in the open position. Thisstreamlined flow passage in which the disc 54 is entirely removed fromthe flow path when the disc 54 in the open position eliminates the chokearea that other discs would create by remaining in the flow path.Additionally, using the two shafts 66, 64 avoids a shaft running throughthe interior chamber 32 and obstructing the flow. This provides a lowerDelta P, i.e., there is less pressure drop than other valves because thedisc 54 and other valve components such as a shaft are not within theflow path of the flow media. The unobstructed flow path provided by theinternal profile also allows for the piggability of the triple valveassembly 2, allowing for a increased ease of maintenance and cleaning ofthe triple valve assembly 2 by a valve or pipe pig.

The internal provision of the valve body 4 also provides one or moreanti-rotation features or edges 122. In some embodiments, oneanti-rotation feature or edge 122 is defined by the meeting of thetubular portion 16 to the valve body 4 and the side portion 14, as shownin FIGS. 5C and 5D, and also in FIG. 4A. The disc 54 is operable to movebetween the open position in which the disc 54 resides within the sideportion 14, and the closed position in which the disc 54 interfaces withthe seat ring 30. The anti-rotation edge 122 prevents the disc 54 fromover rotating such that the disc 54 does not obstruct the flow path whenthe disc 54 is in the open position. In some embodiments, anotheranti-rotation edge 123 prevents the disc 54 from over rotating when thedisc 54 is rotated to the closed position, such that the disc 54 remainsinterfaced with the seat and does not allow for any flow media to passtherethrough.

As also illustrated in FIG. 5C, the internal profile of the unibodytriple valve assembly 2 includes a seat alignment portion 124 and athreaded annulus 126. The seat alignment portion 124 includes a widersection adjacent the threaded annulus 126 and a narrower sectionadjacent the interior chamber 32 of the valve body 4. The wider sectionand narrower section of the seat alignment portion 124 matches theprofile of the seat ring 30, such as shown in FIG. 7 . The matchingprofiles of the seat alignment portion 124 and the seat ring 30,together with the locator 102, allows for the self-centering of the seatring 30 into the seat alignment portion 124, reducing installation errorduring installation of the seat ring 30. Once the seat ring 30 isinstalled, the sealing component 112, which can be a laminated seal, isinstalled on the seat ring 30. In some embodiments, the seal 112 can beincluded with the seat ring 30 and installed contemporaneously with theseat ring 30 into the triple valve assembly 2. The threaded retainerring 110, such as shown in FIG. 6 , is threadedly engaged with thethreaded annulus 126 to create a tight seal between the retainer ring110 and the seat ring 30, with the seal 112 disposed between theretainer ring 110 and the seat ring 30.

FIG. 6 illustrates the retainer ring 110 in accordance with variousembodiments of this disclosure. As described herein, once the seat ring30 is installed, the sealing component 112, which can be a laminatedseal, is installed on the seat ring 30. In some embodiments, the seal112 can be included with the seat ring 30 and installedcontemporaneously with the seat ring 30 into the triple valve assembly2. As shown in FIG. 6 , the threaded retainer ring 110 includes athreaded circumferential surface 128 that threadedly engages with thethreaded annulus 126 of the flange 22 to create a tight seal between theretainer ring 110 and the seat ring 30, with the seal 112 disposedbetween the retainer ring 110 and the seat ring 30. Therefore, if any ofthe seat ring 30, the retainer ring 110, or the seal 112 needs to bemaintained or replaced, the retainer ring 110 can be threadedly removedfrom the threaded annulus 126 to allow removal of the seat components.Since the seat ring 30, the retainer ring 110, and the seal 112 can beaccessed and removed in this manner, the triple valve assembly 2 neednot be re-manufactured whenever these components 30, 110, and 112 aredamaged or otherwise no longer fit for use.

Referring now to FIGS. 7, 8A, and 8B, FIG. 7 illustrates a perspectiveview of the seat ring 30 in accordance with various embodiments of thisdisclosure, and FIGS. 8A and 8B illustrate a side view and a perspectiveview, respectively, of the elliptical seal ring 52 in accordance withvarious embodiments of this disclosure. The seat ring 30 includes afirst section 130 and a second section 132, where, in some embodiments,the first section 130 is of a wider diameter than the second section132. The respective profiles of the first section 130 and the secondsection 132 match the profile of the seat alignment portion 124 of theunibody valve as shown for example in FIG. 5C. It will be understoodthat the profiles of both the seat ring 30 and the seat alignmentportion 124 could be altered, such that the profiles still match forplacement of the seat ring 30 within the valve. The seat ring 30 alsoincludes an indent, opening, or notch 108 that interfaces with thelocator 102 described herein to assist with proper placement of the seatring 30 in the valve.

With respect to the laminated seal ring 52 illustrated in FIGS. 8A and8B, as described herein, the disc assembly 50 is configured as alaminate structure that includes the elliptical seal ring 52 that iscoupled to the disc 54 by the seal retainer disc 60 and the plurality offasteners 62. In this way, the seal ring 52 is removably coupled to thedisc 54, such that it may be replaced if worn or damaged. For example,an operator may remove the fasteners 62 and the seal ring 52 and installa new seal ring, securing the seal ring with the seal retainer disc 60and fasteners 62. The seal ring 52 engages a valve seat 136 created ofseat ring 30 when the valve and disc 54 are in the closed position. Itshould be understood that, in some embodiments, the disc assembly,including the disc, arms, stems and sealing element, may be made as asingle piece, or the disc, arms and sealing element may be made as asingle piece, which is connected to the stems. The gaskets and sealingelements may be made of graphite and/or commercial grade stainlesssteel.

In various embodiments of this disclosure, the valve seat 136 is aconcave surface, providing a unique elliptical third offset togetherwith the shape of the seal ring 52. The seal ring 52 includes a convexlycurved dome shape, or elliptical profile, mating with the concavelyshaped valve seat 136, having a corresponding elliptical profile. Theconfiguration of the disc assembly 50 is designed to allow frictionlessopening and closing of the disc assembly to reduce the required torqueneeded to move or stroke the valve between open and closed positions.The seating creating by the valve seat 136 and the seal ring 52 providesfor a unique elliptical third offset of the triple valve assembly 2.

FIGS. 9A-9D illustrate various views of the offsets of the triple valveassembly 2 in accordance with various embodiments of this disclosure.FIG. 9A illustrates a cross-sectional view of the triple valve assembly2 showing one example of a triple offset in accordance with variousembodiments of this disclosure. FIG. 9B illustrates an exampleelliptical third offset from the perspective of the seat ring 30 inaccordance with various embodiments of this disclosure. FIG. 9Cillustrates an example elliptical third offset from the perspective ofthe seal ring 52 in accordance with various embodiments of thisdisclosure. FIG. 9D illustrates an enlarged view of a first portion 146of the seal ring 52 in accordance with various embodiments of thisdisclosure.

As shown in FIG. 9A, the position of the shafts 64, 66 relative to theseating surface of the valve is offset from the valve centerline inthree axes to allow for frictionless seating and unseating of the valveas well as creating a leak tight sealing of the valve when in the closedposition. The first offset and second offsets are relative to thevertical and horizontal centerline 90, 92 of the valve. These offsetsaid with seating the valve when moving or stroking the valve closed byproviding additional moment forces against the disc assembly when thevalve is pressurized. The third offset is an elliptical centerline ofthe seating and seal centerlines, which make frictionless opening andclosing of the valve possible. In one embodiment, the disc 54 defines acentral horizontal plane 94 offset from the rotation axis 68 relative tothe stem/shaft centerline 92 (offset 1). The centerline axis 96 of thedisc parallel to the centerline 90, and orthogonal to the plane 94, isoffset from the rotation axis 68 (offset 2). The valve seat includes afirst portion 98 that is non-parallel to a second portion 100 of thevalve seat, or forms an angle (offset 3), allowing the valve to rotateand seal.

The first offset can thus be created by the axis 68 of the shaft beingbehind the centerline 94 of the sealing point of the disc 54 to thevalve seat 136. The second offset can thus be created by the axis 68 ofthe shaft being eccentric to the center of the valve or pipe line. Thethird offset is defined by the geometry of the seat, creating anelliptical shape of the disc and seat. The triple offset design of theassembly 2 allows for the disc to seal against the seat withoutfriction, and to provide a tight shutoff while using lower torque.

As illustrated in FIGS. 9B and 9C, the unique third offset of thevarious embodiments of this disclosure is created by the geometry of thevalve seat 136 and the seal ring 52. As described herein, the valve seat136 of the seat ring 30 can be a concave surface. As shown in FIG. 9B,the offset is at least partially defined by a first line 138 alignedwith a first portion 137 of the concave valve seat 136 and a second line140 aligned with a second portion 139 of the concave valve seat 136. Asillustrated in FIG. 9B, the first portion 137 is non-parallel to thesecond portion 139. For example, the first portion 137 can include anincreased or longer incline than that of the second portion 139. It willbe understood that since the concave valve seat 136 is circular, therecan be a gradual change around the circular surface to reach thedifferences in incline of the first and second portions 137, 139. Othervalves typically include a flat spot or edge on the seat and/or disc,but the third offset included in the various embodiments of thisdisclosure provide a continuously changing angle that never reacheszero. The seat ring 30 is oriented such that the concave valve seat 136faces an interior of the valve towards the location of the disc 54within the valve. A vertex 142 of the first and second lines 138, 140 isdisposed a distance from the centerline axis 90, defining angles and/orarcs of the elliptical offset between a seat cone axis 144 extendingfrom the vertex 142 towards the centerline 90 and each of the first andsecond lines 138, 140. For instance, in the example of FIG. 9B, an anglebetween the seat cone axis 144 and the second line 140 is 49.5 degrees.

As shown in FIG. 9B, additional angles of the elliptical third offsetare defined by the centerline 90 and the first and second lines 138,140. An overall angle defined by the first and second lines 138, 140 isshown for example as being 99°±0.25°. Sub-angles are defined by each ofthe first and second lines 138, 140 and the centerline 90. As shown inFIG. 9B, for example, and angle between the first line 138 and thecenterline 90 is 39° and an angle between the second line 140 and thecenterline 90 is 60°±0.12°. Thus, the angle between the centerline 90and the first line 138 created by the first portion 137 is smaller thanthe angle between the centerline 90 and the second line 140 created bythe second portion 139. It will be understood that some variations inthe angles, distances, and other measurements shown in FIG. 9B can beallowed without deviating from the scope of this disclosure.

As shown in FIGS. 9C and 9D, the seal ring 52 installed on the disc 54by the seal retainer disc 60 includes a first portion 146 that meetswith the first portion 137 of the valve seat 136 of the seat ring 30 anda second portion 148 that meets with the second portion 139 of the valveseat 136 when the disc 54 rotates to the closed position. The firstportion 146 is non-parallel to the second portion 148. For example, thefirst portion 146 can include a decreased or shorter incline than thatof the second portion 148. It will be understood that since the sealring 52 is circular, there can be a gradual change around the circularsurface to reach the differences in incline of the first and secondportions 146, 148. Other valves typically include a flat spot or edge onthe seat and/or disc, but the third offset included in the variousembodiments of this disclosure provide a continuously changing anglethat never reaches zero. The first and second lines 138, 140 alsocorrespond to the first portion 146 and the second portion 148,respectively, as shown in FIG. 9C. The seat cone axis 144 is illustratedin FIG. 9C as continuing to run through the seal ring 52, providing asimilar angle of 49.5° as illustrated in FIG. 9B. As also shown in FIG.9C, a complementary overall angle of 99° is shown as corresponding tothe overall angle illustrated in FIG. 9B. Additionally, FIG. 9Cillustrates sub-angles defined by the first and second lines 138 and 140and the centerline 90, such as an angle between second line 140 andcenterline 90 of 60°, that complement the angles illustrated in FIG. 9B.It will be understood that some variations in the angles, distances, andother measurements shown in FIG. 9C can be allowed without deviatingfrom the scope of this disclosure.

The unique third offset created by the geometry of the loose valve seat136 and the laminated seal ring 52 provide for improved frictionlesssealing, allowing for repeatable sealing with an extended valve life,while also providing tight shut off of the valve using lower torque.

FIGS. 10A-10E illustrate various views of the valve disc 54 and theshaft 66 in accordance with various embodiments of this disclosure. FIG.10A illustrates an end view of the valve disc 54 in accordance withvarious embodiments of this disclosure. FIG. 10B illustrates a side viewof the valve disc 54 in accordance with various embodiments of thisdisclosure. FIG. 10C illustrates a perspective view of the shaft 66 inaccordance with various embodiments of this disclosure. FIG. 10Dillustrates a perspective view of the valve disc 54 in accordance withvarious embodiments of this disclosure. FIG. 10E illustrates aperspective view of the valve disc 54 installed on the shaft 66 inaccordance with various embodiments of this disclosure.

The disc 54 includes the first and second arms 56, 58, which aresituated tangentially to the disc 54, thereby ensuring that thepositions of the arms 56, 58 are outside the flow path of the media, orflow passageways 26, 28 projected along the longitudinal axis 12. Thefirst and second arms 56, 58 extend from the top and bottom of the disc54 respectively, with each of the first and second arms having a hub 80,82 for non-rotatably coupling the disc 54 to the first and second stemportions 66, 64 respectively. The disc arms 56, 58 are mounted on thestems/shafts 66, 64, with the stem/shafts 66, 64 being rotated by anoperator or actuator, which rotates the disc assembly between the closedposition and the open position.

As illustrated in FIGS. 10C-10E, in various embodiments of thisdisclosure, one or more of the hubs 80, 82 of the disc 54 can includeopenings or apertures in a polygonal shape to provide a poka yokeconnection between the disc 54 and one or more of the shafts 66, 64. Forexample, as illustrated in FIGS. 10C and 10D, the shaft 66 can include apolygonal end 67 that matches the polygonal shape of the hub 80 of thedisc 54. The matching polygonal shapes of the polygonal hub 80 and thepolygonal end 67 of the shaft 66 provides a unique polygonal connectionbetween the shaft 66 and the hub 80 such that the shaft 66 is receivedinto the hub 80 in a predetermined orientation. In some embodiments, thepolygonal shape used is a non-symmetrical or irregular shape such thatthe shaft 66 can only be received into the hub 80 in one particularrotational position of the shaft 66. It will be understood that,although FIGS. 10C-10E illustrate one example polygonal shape, variouspolygonal shapes can be used, including regular or irregular polygonalshapes, convex or concave polygonal shapes, and/or simple or complexpolygonal shapes. It will be understood that the shaft 64 and the hub 82can also be polygonal in a similar manner to provide for a poka yokeconnection between the shaft 64 and the disc 54. The polygonalconnection between the one or more of the shafts 66, 64 and one or moreof the hubs 80, 82 also provide for 100% torque transmission betweenfrom the shafts 66, 64 to the disc 54.

The full bore profile and lug design of the disc 54 assists withachieving smooth flow and strength in media transport using the assembly2. Additionally, the disc 54 includes a seal guide 55 that matches theprofile of the seal ring 52, providing a poka yoke installation of theseal ring 52 on the disc 54 to ensure sufficient sealing between thedisc 54 and the valve seat 136 of the seat ring 30.

As shown in FIG. 10E, the disc 54 moves to seal the flow path byinterfacing with the seat ring 30. As described in the variousembodiments herein, the disc 54 does not obstruct the flow path 24, 26,28 when in the open position. In particular, the disc 54 is rotatablewithin the interior chamber 32 between the closed position, wherein thedisc closes the second flow passageway 28, and the open position,wherein at least one of the first and second flow passageways, or both,are completely unobstructed between the first and second end portions 8,10 of the valve body. In addition, in various embodiments, since theshafts 64, 66 are separate shafts, the shafts also do not obstruct theflow paths 24, 26, 28.

In one example embodiment, a valve comprises a valve body comprisingfirst and second ends spaced apart along a longitudinal axis and acentral portion disposed between the first and second ends, wherein thefirst and second ends define first and second flow passagewaysrespectively, and wherein the central portion defines an interiorchamber, a stem rotatably supported by the valve body about a rotationaxis, and a disc coupled to the stem, wherein the disc is rotatablewithin the interior chamber between a closed position, wherein the disccloses one of the first or second flow passageways, and an openposition, wherein at least one of the first and second flow passagewaysis completely unobstructed between the first and second ends of thevalve body when projected along the longitudinal axis.

In one or more of the above examples, the disc defines a central planeoffset from the rotation axis.

In one or more of the above examples, a centerline axis of the discorthogonal to the central plane is offset from the rotation axis.

In one or more of the above examples, the valve body defines a valveseat engaged by the disc when the disc is in the closed position,wherein a first portion of the valve seat are non-parallel to a secondportion of the valve seat.

In one or more of the above examples, the stem comprises a first stemportion supported by the valve body and coupled to a top of the disc,and a second stem portion supported by the valve body and coupled to thebottom of the disc, wherein the first and second stem portions arespaced apart on opposite sides of, and do not project into, the at leastone of the first and second flow passageways projected along thelongitudinal axis.

In one or more of the above examples, the valve further comprises firstand second arms extending from the top and bottom of the discrespectively, each of the first and second arms comprising a hub coupledto one of the first and second stem portions.

In one or more of the above examples, both of the first and second flowpassageways are completely unobstructed between the first and secondends of the valve body when each of the first and second flowpassageways is projected along the longitudinal axis.

In one or more of the above examples, the first and second flowpassageways are coaxial.

In one or more of the above examples, the first and second flowpassageways have respective first and second cross-sectional areasdefined orthogonal to the longitudinal axis, wherein the firstcross-sectional area is the same as the second cross-sectional area.

In one or more of the above examples, the valve body defines a valveseat, and wherein further comprising a seal ring removably coupled tothe disc, wherein the seal ring engages the valve seat when the disc isin the closed position.

In one or more of the above examples, the interior chamber comprises anenlarged side portion positioned outside of the at least one of thefirst and second flow passageways projected along the longitudinal axis,wherein the disc is disposed in the side portion when the valve is inthe open position.

In another example embodiment, a valve comprises a valve body comprisingfirst and second ends spaced apart along a longitudinal axis and acentral portion disposed between the first and second ends, wherein thefirst and second ends define first and second flow passagewaysrespectively, and wherein the central portion defines an interiorchamber, a stem comprising a first stem portion supported by a top ofthe valve body and a second stem portion supported by a bottom of thevalve body, wherein the first and second stem portions are spaced aparton opposite sides of, and do not project into, at least one of the firstand second flow passageways when projected along the longitudinal axis,wherein the first and second stem portions are co-axial and define arotation axis, and a valve comprises a disc having a top coupled to thefirst stem portion and a bottom coupled to the second stem portion,wherein the valve is rotatable within the interior chamber between aclosed position, wherein the disc closes one of the first or second flowpassageways, and an open position, wherein at least one of the first andsecond flow passageways is completely unobstructed by the valve betweenthe first and second ends of the valve body when projected along thelongitudinal axis.

In one or more of the above examples, the disc defines a central planeoffset from the rotation axis.

In one or more of the above examples, a centerline axis of the discorthogonal to the central plane is offset from the rotation axis.

In one or more of the above examples, the valve body defines a valveseat engaged by the disc when the disc is in the closed position,wherein a first portion of the valve seat are non-parallel to a secondportion of the valve seat.

In one or more of the above examples, the valve further comprises firstand second arms extending from the top and bottom of the discrespectively, each of the first and second arms comprising a hub coupledto one of the first and second stem portions.

In one or more of the above examples, both of the first and second flowpassageways are completely unobstructed between the first and secondends of the valve body when each of the first and second flowpassageways is projected along the longitudinal axis.

In one or more of the above examples, the first and second flowpassageways are coaxial.

In one or more of the above examples, the first and second flowpassageways have respective first and second cross-sectional areasdefined orthogonal to the longitudinal axis, wherein the firstcross-sectional area is the same as the second cross-sectional area.

In one or more of the above examples, the valve body defines a valveseat, and wherein the valve comprises a seal ring removably coupled tothe disc, wherein the seal ring engage the valve seat when the valve isin the closed position.

In one or more of the above examples, the interior chamber comprises anenlarged side portion positioned outside of the at least one of thefirst and second flow passageways projected along the longitudinal axis,wherein the disc is disposed in the side portion when the valve is inthe open position.

In another example embodiment, a method of operating a valve comprisesrotating a valve comprising a disc in a valve body about a rotation axisbetween an open position and a closed position, wherein the valve bodycomprises first and second ends spaced apart along a longitudinal axisand a central portion disposed between the first and second ends,wherein the first and second ends define first and second flowpassageways respectively, and wherein the central portion defines aninterior chamber, wherein the disc closes one of the first or secondflow passageways in the closed position, and wherein at least one of thefirst and second flow passageways is completely unobstructed between thefirst and second ends of the valve body when projected along thelongitudinal axis when the valve is in the open position.

In one or more of the above examples, rotating the valve comprisesrotating a stem about the rotation axis, wherein the disc is coupled tothe stem, and rotating the disc within the interior chamber.

In one or more of the above examples, the disc defines a central planeoffset from the rotation axis.

In one or more of the above examples, a centerline axis of the discorthogonal to the central plane is offset from the rotation axis.

In one or more of the above examples, the valve body defines a valveseat engaged by the disc when the disc is in the closed position,wherein a first portion of the valve seat are non-parallel to a secondportion of the valve seat.

In one or more of the above examples, the stem comprises a first stemportion supported by the valve body and coupled to a top of the disc,and a second stem portion supported by the valve body and coupled to thebottom of the disc, wherein the first and second stem portions arespaced apart on opposite sides of, and do not project into, the at leastone of the first and second flow passageways projected along thelongitudinal axis.

In one or more of the above examples, the valve further comprises firstand second arms extending from the top and bottom of the discrespectively, each of the first and second arms comprising a hub coupledto one of the first and second stem portions.

In one or more of the above examples, both of the first and second flowpassageways are completely unobstructed between the first and secondends of the valve body when each of the first and second flowpassageways is projected along the longitudinal axis when the valve isin the open position.

In one or more of the above examples, the first and second flowpassageways are coaxial.

In one or more of the above examples, the first and second flowpassageways have respective first and second cross-sectional areasdefined orthogonal to the longitudinal axis, wherein the firstcross-sectional area is the same as the second cross-sectional area.

In one or more of the above examples, the valve body defines a valveseat, and wherein the valve comprises a first seal ring coupled to thedisc, wherein the first seal ring engage the valve seat when the valveis in the closed position, and further comprising removing the firstseal ring and installing a second seal ring on the disc.

In one or more of the above examples, the interior chamber comprises anenlarged side portion positioned outside of the at least one of thefirst and second flow passageways projected along the longitudinal axis,wherein the disc is disposed in the side portion when the valve is inthe open position.

In one or more of the above examples, the disc comprises an ellipticalseal.

In one or more of the above examples, the first end of the bodycomprises a bore, and further comprising a seat ring disposed in thebore and defining at least in part the first flow passageway.

In one or more of the above examples, the seat ring comprises a concavesealing surface, and wherein disc engages the sealing surface whenrotated to the closed position.

In one or more of the above examples, the valve further comprises aretainer ring securing the seat ring to the body.

In one or more of the above examples, the valve comprises a sealingcomponent disposed between the seat ring and the retainer ring.

In one or more of the above examples, the valve further comprises alocator interfacing between the seat ring and the body.

In one or more of the above examples, the locator comprises a pindisposed in an opening defined in part by the valve body and in part byan outer surface of the seat ring.

In another example embodiment, a valve comprises a valve body comprisingfirst and second ends spaced apart along a longitudinal axis and acentral portion disposed between the first and second ends, wherein thefirst end comprises a bore, a valve moveably disposed in the centralportion, wherein the valve is moveable between open and closedpositions, a seat ring disposed in the bore and defining at least inpart a flow passageway, and a locator interfacing between the seat ringand the body, wherein the locator positionally locates the seat ringrelative to the body.

In one or more of the above examples, the locator comprises a pindisposed in an opening defined in part by the valve body and in part byan outer surface of the seat ring.

In one or more of the above examples, the seat ring comprises a concavesealing surface, and wherein the valve comprises a disc engaging thesealing surface when moved to a closed position.

In one or more of the above examples, comprising a retainer ringsecuring the seat ring to the body.

In one or more of the above examples, the valve comprises a sealingcomponent disposed between the seat ring and the retainer ring.

In another example embodiment, a unibody valve comprises a valve bodyincluding a first end and a second end spaced apart along a longitudinalaxis and a central portion disposed between the first end and the secondend, wherein the first end and the second end define a first flowpassageway and a second flow passageway, respectively, and wherein thecentral portion defines an interior chamber, and a disc disposed withinthe interior chamber, wherein the interior chamber includes an enlargedside portion positioned outside of the at least one of the first flowpassageway and the second flow passageway projected along thelongitudinal axis, wherein the disc is disposed in the enlarged sideportion when in an open position.

In one or more of the above examples, the unibody valve furthercomprises an anti-rotation edge disposed on at least one side of theenlarged side portion, wherein the anti-rotation edge prevents the discfrom rotating beyond the anti-rotation edge.

In one or more of the above examples, the anti-rotation edge is definedby a meeting of one of the first flow passageway and the second flowpassageway with the interior chamber and the enlarged side portion.

In one or more of the above examples, the unibody valve furthercomprises another anti-rotation edge disposed on an opposite side of thelongitudinal axis from the enlarged side portion.

In one or more of the above examples, the unibody valve furthercomprises a stem rotatably supported by the valve body about a rotationaxis, wherein the disc is coupled to the stem and is rotatable withinthe interior chamber between a closed position, wherein the disc closesone of the first flow passageway or the second flow passageway, and theopen position, wherein at least one of the first flow passageway and thesecond flow passageway is completely unobstructed between the first endand the second end of the valve body when projected along thelongitudinal axis.

In one or more of the above examples, the disc defines a central planeoffset from the rotation axis.

In one or more of the above examples, a centerline axis of the discorthogonal to the central plane is offset from the rotation axis.

In one or more of the above examples, the valve body defines a valveseat engaged by the disc when the disc is in the closed position,wherein a first portion of the valve seat is non-parallel to a secondportion of the valve seat.

In one or more of the above examples, the stem includes a first stemportion supported by the valve body and coupled to a top of the disc,and a second stem portion supported by the valve body and coupled to abottom of the disc, wherein the first and second stem portions arespaced apart on opposite sides of, and do not project into, the at leastone of the first flow passageway and the second flow passagewayprojected along the longitudinal axis.

In one or more of the above examples, the disc includes first and secondarms extending from the top and the bottom of the disc respectively,each of the first and second arms including a hub coupled to one of thefirst and second stem portions.

In one or more of the above examples, both of the first flow passagewayand the second flow passageway are completely unobstructed between thefirst end and the second end of the valve body when each of the firstflow passageway and the second flow passageway is projected along thelongitudinal axis.

In one or more of the above examples, the first flow passageway and thesecond flow passageway are coaxial.

In one or more of the above examples, the first flow passageway and thesecond flow passageway have respective first and second cross-sectionalareas defined orthogonal to the longitudinal axis, wherein the firstcross-sectional area is the same as the second cross-sectional area.

In one or more of the above examples, the valve body is piggable whenthe disc is in the open position.

In one or more of the above examples, the first end of the valve bodyincludes a bore, and further comprising a seat ring disposed in the boreand defining at least in part the first flow passageway.

In one or more of the above examples, the seat ring includes a concavesealing surface, and wherein the disc engages the concave sealingsurface when rotated to a closed position.

In one or more of the above examples, the unibody valve furthercomprises a retainer ring securing the seat ring to the valve body.

In one or more of the above examples, the unibody valve furthercomprises a sealing component disposed between the seat ring and theretainer ring.

In one or more of the above examples, the unibody valve furthercomprises a locator interfacing between the seat ring and the valvebody.

In one or more of the above examples, the locator includes a pindisposed in an opening defined in part by the valve body and in part byan outer surface of the seat ring.

In another example embodiment, a valve comprises a valve body includinga first end and a second end spaced apart along a longitudinal axis anda central portion disposed between the first end and the second end,wherein the first end and the second end define a first flow passagewayand a second flow passageway, respectively, and wherein the centralportion defines an interior chamber, a stem rotatably supported by thevalve body about a rotation axis, wherein the stem includes a polygonalend, and a disc disposed within the interior chamber and including apolygonal aperture to receive the polygonal end of the stem.

In one or more of the above examples, the polygonal aperture of the discand the polygonal end of the stem include matching polygonal shapes toassist with installation of the stem to the disc and to provideincreased torque transmission from the stem to the disc.

In one or more of the above examples, the disc is rotatable within theinterior chamber between a closed position, wherein the disc closes oneof the first flow passageway or the second flow passageway, and an openposition, wherein at least one of the first flow passageway and thesecond flow passageway is completely unobstructed between the first endand the second end of the valve body when projected along thelongitudinal axis.

In one or more of the above examples, the stem includes a first stemportion supported by the valve body and coupled to a top of the disc,and a second stem portion supported by the valve body and coupled to abottom of the disc, wherein the first and second stem portions arespaced apart on opposite sides of, and do not project into, the at leastone of the first flow passageway and the second flow passagewayprojected along the longitudinal axis.

In one or more of the above examples, the disc includes first and secondarms extending from the top and the bottom of the disc respectively,each of the first and second arms including a hub coupled to one of thefirst and second stem portions.

In one or more of the above examples, one of the first and second stemportions include the polygonal end.

In one or more of the above examples, the hub of one of the first andsecond arms includes the polygonal aperture.

In one or more of the above examples, the first and second stem portionsinclude a first and second polygonal end, respectively, and the hub ofeach of the first and second arms includes a first and second polygonalaperture, respectively.

In one or more of the above examples, the disc defines a central planeoffset from the rotation axis.

In one or more of the above examples, a centerline axis of the discorthogonal to the central plane is offset from the rotation axis.

In one or more of the above examples, the valve body defines a valveseat engaged by the disc when the disc is in a closed position, whereina first portion of the valve seat is non-parallel to a second portion ofthe valve seat.

In one or more of the above examples, the first flow passageway and thesecond flow passageway are coaxial.

In one or more of the above examples, the first flow passageway and thesecond flow passageway have respective first and second cross-sectionalareas defined orthogonal to the longitudinal axis, wherein the firstcross-sectional area is the same as the second cross-sectional area.

In one or more of the above examples, the first end of the valve bodyincludes a bore, and further comprising a seat ring disposed in the boreand defining at least in part the first flow passageway.

In one or more of the above examples, the seat ring includes a concavesealing surface, and wherein the disc engages the concave sealingsurface when rotated to a closed position.

In one or more of the above examples, the disc includes a seal guideoperable to receive a seal ring, wherein the seal ring contacts theconcave sealing surface of the seat ring when the disc engages theconcave sealing surface of the seat ring.

In one or more of the above examples, the seal ring is held between theseal guide and a seal retainer coupled to the disc.

In one or more of the above examples, the valve further comprises aretainer ring securing the seat ring to the valve body.

In one or more of the above examples, the valve further comprises asealing component disposed between the seat ring and the retainer ring.

In one or more of the above examples, the valve further comprises alocator interfacing between the seat ring and the valve body.

In another example embodiment, a valve comprises a valve body includinga first end and a second end spaced apart along a longitudinal axis anda central portion disposed between the first end and the second end,wherein the first end and the second end define a first flow passagewayand a second flow passageway, respectively, and wherein the centralportion defines an interior chamber, wherein the first end of the valvebody includes a bore, and a removable seat disposed in the bore anddefining at least in part the first flow passageway.

In one or more of the above examples, the removable seat includes a seatring.

In one or more of the above examples, a portion of the bore includes aprofile corresponding to and operable to receive the seat ring.

In one or more of the above examples, the valve further comprises aretainer ring securing the seat ring to the valve body.

In one or more of the above examples, the retainer ring threadedlyengages a threaded surface of the bore to secure the seat ring to thevalve body.

In one or more of the above examples, the valve further comprises asealing component disposed between the seat ring and the retainer ring.

In one or more of the above examples, the valve further comprises alocator interfacing between the seat ring and the valve body.

In one or more of the above examples, the locator includes a pindisposed in an opening defined in part by the valve body and in part byan outer surface of the seat ring.

In one or more of the above examples, the valve further comprises a stemrotatably supported by the valve body about a rotation axis and a disccoupled to the stem and rotatable within the interior chamber between aclosed position, wherein the disc closes one of the first flowpassageway or the second flow passageway, and an open position, whereinat least one of the first flow passageway and the second flow passagewayis completely unobstructed between the first end and the second end ofthe valve body when projected along the longitudinal axis.

In one or more of the above examples, the seat ring includes a concavesealing surface, and wherein the disc engages the concave sealingsurface when rotated to the closed position.

In one or more of the above examples, the disc includes a seal ring thatcontacts the concave sealing surface of the seat ring when the discengages the concave sealing surface of the seat ring.

In one or more of the above examples, the seal ring of the disc iselliptical.

In one or more of the above examples, the disc defines a central planeoffset from the rotation axis.

In one or more of the above examples, a centerline axis of the discorthogonal to the central plane is offset from the rotation axis.

In one or more of the above examples, a first portion of the seat ringis non-parallel to a second portion of the seat ring.

In one or more of the above examples, the stem includes a first stemportion supported by the valve body and coupled to a top of the disc,and a second stem portion supported by the valve body and coupled to abottom of the disc, wherein the first and second stem portions arespaced apart on opposite sides of, and do not project into, the at leastone of the first flow passageway and the second flow passagewayprojected along the longitudinal axis.

In one or more of the above examples, the disc includes first and secondarms extending from the top and the bottom of the disc respectively,each of the first and second arms including a hub coupled to one of thefirst and second stem portions.

In one or more of the above examples, both of the first flow passagewayand the second flow passageway are completely unobstructed between thefirst end and the second end of the valve body when each of the firstflow passageway and the second flow passageway is projected along thelongitudinal axis.

In one or more of the above examples, the first flow passageway and thesecond flow passageway are coaxial.

In one or more of the above examples, the first flow passageway and thesecond flow passageway have respective first and second cross-sectionalareas defined orthogonal to the longitudinal axis, wherein the firstcross-sectional area is the same as the second cross-sectional area.

In another example embodiment, a valve comprises a valve body includinga first end and a second end spaced apart along a longitudinal axis anda central portion disposed between the first end and the second end,wherein the first end and the second end define a first flow passagewayand a second flow passageway, respectively, and wherein the centralportion defines an interior chamber, wherein the first end of the valvebody includes a bore, a valve seat disposed in the bore including aconcave seating surface, and a disc rotatable within the interiorchamber between an open position and a closed position, wherein the discincludes a seal having a shape corresponding to the concave seatingsurface and wherein the shape of the seal and the concave seatingsurface define an elliptical offset from a centerline of the valve.

In one or more of the above examples, the concave seating surfaceincludes a first portion and a second portion both at an inclinerelative to the centerline.

In one or more of the above examples, the seal of the disc includes afirst portion and a second portion, wherein the first portion of theseal and the second portion of the seal contact the first portion of theconcave seating surface and the second portion of the concave seatingsurface, respectively, when the disc rotates to the closed position.

In one or more of the above examples, the first portion of the concaveseating surface is non-parallel to the second portion of the concaveseating surface.

In one or more of the above examples, the first portion of the concaveseating surface includes a longer incline than the second portion of theconcave seating surface.

In one or more of the above examples, the longer incline of the firstportion of the concave seating surface results in a reduced anglebetween the first portion of the concave seating surface and thecenterline than that of an angle between the second portion of theconcave seating surface and the centerline.

In one or more of the above examples, the seal in elliptical.

In one or more of the above examples, the seal of the disc includes afirst portion and a second portion, wherein the first portion of theseal and the second portion of the seal contact the first portion of theconcave seating surface and the second portion of the concave seatingsurface, respectively, when the disc rotates to the closed position.

In one or more of the above examples, the first portion of the seal isnon-parallel to the second portion of the seal.

In one or more of the above examples, the first portion of the sealincludes a shorter incline than the second portion of the seal.

In one or more of the above examples, the valve seat is a seat ringoperable to be removably installed into the bore.

In one or more of the above examples, the valve further comprises a stemrotatably supported by the valve body about a rotation axis, wherein thedisc is coupled to the stem in order to rotate within the interiorchamber between the closed position, wherein the disc closes one of thefirst flow passageway or the second flow passageway, and the openposition, wherein at least one of the first flow passageway and thesecond flow passageway is completely unobstructed between the first endand the second end of the valve body when projected along thelongitudinal axis.

In one or more of the above examples, the seal of the disc engages theconcave seating surface when the disc is rotated to the closed position.

In one or more of the above examples, the disc defines a central planeoffset from the rotation axis.

In one or more of the above examples, a centerline axis of the discorthogonal to the central plane is offset from the rotation axis.

In one or more of the above examples, the stem includes a first stemportion supported by the valve body and coupled to a top of the disc,and a second stem portion supported by the valve body and coupled to abottom of the disc, wherein the first and second stem portions arespaced apart on opposite sides of, and do not project into, the at leastone of the first flow passageway and the second flow passagewayprojected along the longitudinal axis.

In one or more of the above examples, the disc includes first and secondarms extending from the top and the bottom of the disc respectively,each of the first and second arms including a hub coupled to one of thefirst and second stem portions.

In one or more of the above examples, the valve seat is a seat ringoperable to be removably installed into the bore.

In one or more of the above examples, the valve further comprises afirst stem portion supported by the valve body and coupled to a top ofthe disc, and a second stem portion supported by the valve body andcoupled to a bottom of the disc, wherein the first and second stemportions are spaced apart on opposite sides of, and do not project into,the at least one of the first flow passageway and the second flowpassageway projected along the longitudinal axis, wherein the first stemportion and the second stem portion are rotatably supported by the valvebody about a rotation axis, and wherein the disc closes one of the firstflow passageway or the second flow passageway, and the open position.

In one or more of the above examples, the disc defines a central planeoffset from the rotation axis and a centerline axis of the discorthogonal to the central plane is offset from the rotation axis.

The description in the present application should not be read asimplying that any particular element, step, or function is an essentialor critical element that must be included in the claim scope. The scopeof patented subject matter is defined only by the allowed claims.Moreover, none of the claims invokes 35 U.S.C. § 112(f) with respect toany of the appended claims or claim elements unless the exact words“means for” or “step for” are explicitly used in the particular claim,followed by a participle phrase identifying a function. Use of termssuch as (but not limited to) “mechanism,” “module,” “device,” “unit,”“component,” “element,” “member,” “apparatus,” “machine,” “system,”“processor,” or “controller” within a claim is understood and intendedto refer to structures known to those skilled in the relevant art, asfurther modified or enhanced by the features of the claims themselves,and is not intended to invoke 35 U.S.C. § 112(f).

While the invention has been described with reference to a preferredembodiment, it will be understood by those skilled in the art thatvarious changes may be made, and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims. While this disclosure has described certain embodiments andgenerally associated methods, alterations and permutations of theseembodiments and methods will be apparent to those skilled in the art.Accordingly, the above description of example embodiments does notdefine or constrain this disclosure. Other changes, substitutions, andalterations are also possible without departing from the spirit andscope of this disclosure, as defined by the following claims.

What is claimed is:
 1. A valve comprising: a valve body including: afirst end and a second end spaced apart along a longitudinal axis; acentral portion disposed between the first end and the second end,wherein the first end and the second end define a first flow passagewayand a second flow passageway, respectively, and wherein the centralportion defines an interior chamber, wherein the first end of the valvebody includes a bore; a valve seat disposed in the bore including aconcave seating surface, the concave seating surface including a firstinclined portion and a second inclined portion, wherein an angle of thefirst inclined portion is different than an angle of the second inclinedportion; a disc rotatable within the interior chamber between an openposition and a closed position; and a seal removably coupled to thedisc, wherein an external surface of the seal includes a set of steps,disposed along an inclined portion of the disc, incrementally changingan external diameter of the seal, wherein each step includes ahorizontal portion that is parallel with a central axis of the seal anda vertical portion that is orthogonal to the central axis of the seal,wherein the seal and the concave seating surface define an ellipticaloffset from a centerline of the valve, wherein the first inclinedportion and the second inclined portion are inclined relative to thecenterline, wherein the inclined portion of the seal of the discincludes a first portion and a second portion, wherein the first portionof the seal and the second portion of the seal contact the firstinclined portion of the concave seating surface and the second inclinedportion of the concave seating surface, respectively, when the discrotates to the closed position, wherein the first portion of the seal isnon-parallel to the second portion of the seal, and wherein the firstportion of the seal includes a shorter incline than the second portionof the seal.
 2. The valve of claim 1, wherein the first inclined portionof the concave seating surface is non-parallel to the second inclinedportion of the concave seating surface.
 3. The valve of claim 2, whereinthe first inclined portion of the concave seating surface includes alonger incline than the second inclined portion of the concave seatingsurface.
 4. The valve of claim 3, wherein the longer incline of thefirst inclined portion of the concave seating surface results in areduced angle between the first inclined portion of the concave seatingsurface and the centerline than that of an angle between the secondinclined portion of the concave seating surface and the centerline. 5.The valve of claim 4, wherein the seal has an elliptical profile.
 6. Thevalve of claim 1, wherein the valve seat is a seat ring operable to beremovably installed into the bore.
 7. The valve of claim 6, furthercomprising: a stem rotatably supported by the valve body about arotation axis, wherein the disc is coupled to the stem in order torotate within the interior chamber between the closed position, whereinthe disc closes one of the first flow passageway or the second flowpassageway, and the open position, wherein at least one of the firstflow passageway and the second flow passageway is completelyunobstructed between the first end and the second end of the valve bodywhen projected along the longitudinal axis.
 8. The valve of claim 7,wherein the seal of the disc engages the concave seating surface whenthe disc is rotated to the closed position.
 9. The valve of claim 8,wherein the disc defines a central plane offset from the rotation axis.10. The valve of claim 9, wherein a centerline axis of the discorthogonal to the central plane is offset from the rotation axis. 11.The valve of claim 10, wherein the stem includes a first stem portionsupported by the valve body and coupled to a top of the disc, and asecond stem portion supported by the valve body and coupled to a bottomof the disc, wherein the first and second stem portions are spaced aparton opposite sides of, and do not project into, the at least one of thefirst flow passageway and the second flow passageway projected along thelongitudinal axis.
 12. The valve of claim 11, wherein the disc includesfirst and second arms extending from the top and the bottom of the discrespectively, each of the first and second arms including a hub coupledto one of the first and second stem portions.
 13. The valve of claim 1,wherein the valve seat is a seat ring operable to be removably installedinto the bore.
 14. The valve of claim 13, further comprising: a firststem portion supported by the valve body and coupled to a top of thedisc, and a second stem portion supported by the valve body and coupledto a bottom of the disc, wherein the first and second stem portions arespaced apart on opposite sides of, and do not project into, the at leastone of the first flow passageway and the second flow passagewayprojected along the longitudinal axis, wherein the first stem portionand the second stem portion are rotatably supported by the valve bodyabout a rotation axis, and wherein the disc closes one of the first flowpassageway or the second flow passageway.
 15. The valve of claim 14,wherein the disc defines a central plane offset from the rotation axisand a centerline axis of the disc orthogonal to the central plane isoffset from the rotation axis.